1. Field of the Invention
The present invention relates to a pharmaceutical composition for preventing and treating endometriosis which comprises Puerariae Flos extract as an active ingredient, and a health food comprising the same.
2. Description of the Related Art
Endometriosis is a one of the most common gynecological diseases and its attack rate is about 3%˜10% in childbearing age women and 25˜35% in infertile women. This disease is characterized by abnormal proliferation of endometrial tissues in other organs such as ovary, abdominal cavity, digestive track, and urinary bladder than uterus and the implantation theory by Sampson has been accepted as the pathogenesis, which is that endometriosis is developed when endometrial tissues flow backward into abdominal cavity through fallopian tube and are implanted in ovary or peritoneum to grow. Symptoms of endometriosis are dysmenorrhoea, dyspareunia, and pains in other organs invaded (for example, Pneumothorax or hemothorax is observed when the endometrial tissue has invaded in the lung./Ureteral obstruction or hematuria is observed when the endometrial tissue has invaded in the ureter.). This disease can be a reason of infertility in 30˜50% of total endometriosis patients. It has also been reported that endometriosis increases the risk of various cancers including ovarian cancer, renal cell carcinoma, and brain tumor.
Endometriosis cells are completely different from their origin, the normal endometrial cells, in their functions and in their molecular mechanism.
Endometriosis cells are estrogen-responsive but progesterone-unresponsive. Recent reports support the idea that endometriosis cells characterized by uncontrolled proliferation, anti-apoptosis, angiogenesis, migration and invasion, and change in local immune system are very similar to cancer cells in their characteristics (Farquhar, 2007; Fazleabas et al., 2004; Garai et al., 2006; Hastings and Fazleabas, 2003; Hastings and Fazleabas, 2006; Wu et al., 2007) (see FIG. 1). The most representative molecular biological characteristics of endometriosis are closely related to the over-expressions/over-productions of estrogen, prostaglandin, cytokine, and metalloproteinase (Bulun, 2009) (see FIG. 2).
The only and fundamental treatment for endometriosis so far is the surgical operation to eliminate the endometrium but this treatment has the disadvantage of high recurrence rate and might cause difficulty for a woman to have a baby later. For internal treatment for this disease, the conservative management using a pain killer or an anti-inflammatory agent, and the hormone therapy using danzol, progesterone, and gonadotropin-releasing hormone (GnRH) to regulate menstrual cycle have been used, but these are not fundamental treatment and only to alleviate symptoms or pains. Furthermore, the long-term treatment with those hormones causes other side effects (weight gain, fluid overload, fatigue, acne, oily skin, hirsutism, atropic vaginitis, hot flush, muscle spasm, anxiety, and hepatotoxicity). The recurrence rate is also as high as 70%. Endometriosis brings inconvenience in everyday life because of severe pain accompanied and is even a reason of infertility. Therefore, in the aspects of the ‘quality of women's life’ and ‘pregnancy’, this disease has to be considered as significant and as the one that has to be overcome. Nevertheless, a successful preventive and therapeutic method has not been established, yet, and studies on this matter are still in short. Thus, it is required to develop a preventive and therapeutic agent for endometriosis from natural substances that is more natural and thus has less side effects and outperforms the conventional methods such as surgical operation or simple pain management and menstrual cycle control, etc, in women particularly those in childbearing age.
Puerariae Flos is the flower of kudzu (Pueraria thunbergiana). According to the traditional medicine, this flower has been used to eliminate alcoholic poisoning or to relieve melena (Sanrim Gyeongje, Medicine, Puerariae radix). The leaf is also called Pueraria thunbergiana leaf that has been used to stop the bleeding of wound. The stem is called Pueraria thunbergiana stem that has been internally administered to treat laryngopharyngitis or applied externally to treat furuncle, for which Pueraria thunbergiana leaf is burn and powdered. The natural extract of Puerariae Flos long been administered according to the Oriental medicine has been targeted for the study of anti-inflammation and the result was presented in Journal of Ethnopharmacology in 2004 (J. Ethnopharmacol. 2004 September; 94(1):165-73.). The effect of the Puerariae Flos extract on the secretion of growth hormone has also been studied and published (Horm Metab Res. 2004 February; 36(2):86-91.). The effect of the Puerariae Flos and other Leguminosae plants originated materials on the activity of estrogen was also reported in 2005 (Biol Pharm Bull. 2005 March; 28(3):538-40.). According to another report (J Agric Food Chem. 2005 Jul. 27; 53(15):5882-8.), the Puerariae Flos extract could inhibit the reducing effect of beta-hydroxy-beta-methylglutaryl coenzyme A (HMG CoA), and this coenzyme inhibitor could further inhibit the synthesis of cholesterol, more precisely inhibit the synthesis of cholesterol in liver. In 2006, the result of a study saying that Daidzin originated from Puerariae Flos extract could activate choline acetyltransferase, the enzyme to synthesize the neurotransmitter, acethylcholine, bringing the effect of improving amnesia resulted from drug intoxication was reported (Biosci Biotechnol Biochem. 2006 January; 70(1):107-11.). In addition, kakkalide and tectoridin were identified as major components of Puerariae Flos extract (J Nat. Med. 2010 July; 64(3):313-20. Epub 2010 March 31.), and these kakkalide and tectoridin were confirmed to have estrogen effect by affecting estrogen receptor (ER) and estrogen related receptors (ERR1/2), according to the study with menopausal women (Biol Pharm Bull. 2006 June; 29(6):1202-6.).
The present inventors have studied how the extract of Puerariae Flos, the natural substance long been used in Oriental medicine, could affect endometriosis cells. As a result, the present inventors confirmed that the Puerariae Flos extract had the activity of inhibiting the migration of endometriosis cells, inhibiting the adhesion of the cells onto peritoneal cells, and inhibiting the expressions of the characteristic factors of endometriosis, by which the inventors completed this invention with presenting the Puerariae Flos extract as an active ingredient for a composition for preventing and treating endometriosis.